Advanced fiber-optic contact and method

ABSTRACT

An opto-electronic contact, method and connection system can utilize an active opto-electronic converter configured for removable optical engagement with an opposing contact. A barrel housing defines an interior cavity to capture the converter in the interior cavity for external optical engagement to the opposing contact via the first barrel opening for relative movement of the converter axis along the elongation axis, transverse thereto, and oblique thereto to accommodate mating tolerances responsive to engaging the opposing contact. A flexible circuit board assembly can be used to externally electrically interface the converter.

RELATED APPLICATION

This application is a divisional application of copending U.S. patentapplication Ser. No. 13/562,267 filed on Jul. 30, 2012, the disclosureof which is incorporated herein by reference.

BACKGROUND

The present invention is generally related to the field of fiber opticconnectors and, more particularly, to an advanced fiber optic contactthat includes active components.

An electronic rack assembly can define one or more positions each ofwhich is configured for receiving a module. The rack assembly caninclude a connection back plane such that each module can include acomplementary connection arrangement that blind-mates to the connectionback plane when each module is installed. In this way, a large number ofinterface connections can simultaneously be made or broken such thateach module can be conveniently installed and/or replaced. Such rackassemblies, by way of example, have become popular in the avionicsfield.

Data rates have increased between modules, at least in the avionicsfield, due to a desire to provide for high-definition digital video forin-flight entertainment systems, cockpit displays, AFDX (Avionics FullDuplex Switched Ethernet) interconnect protocol and the like.Accordingly, avionics systems and aircraft manufacturers hope to takeadvantage of the extremely high bandwidth and light weight, ease ofrouting, and immunity to electromagnetic interference (EMI) offered bythe optical fiber transport medium. There is a need, therefore, foravionics rack assemblies and associated modules to accommodate fiberoptic connections therebetween. Some standards such as the ARINC 801-804standards, by way of non-limiting example, detail specifications forfiber-optic connector interfaces that can be inserted into an ARINCmodule connector, as well as into rack connectors. These standardspertain to passive optical connectors for blind-mate interfaces that areinserted into industry-standard “Size 8” cavities, so-named due to theapproximate 8 mm diameter of the cavity.

One approach that has been taken on the module side in such systemsemploys an optical converter component inside of the module. The opticalconverter is mounted on a printed circuit board and can support anoptical fiber that serves as a pigtail leading to an ARNIC 801 passivefiber-optic connector for connection to the module external interface.During assembly of a module such as an avionics module, fibersassociated with such optical converter modules must be routed verycarefully through the module between the optical converters and themodule interface. This is fundamentally an operation not suited toautomated assembly techniques, and requires a relatively skilledtechnician. In this regard, optical fibers are easily susceptible todamage due to excessively small bend radius, high heat, handling errors,and the like. Therefore, as packaging densities of avionics modules haveincreased, the routing of optical fibers inside of a module has becomeproblematic. Since manufacturing of modules incorporating both opticalfibers and electrical cabling between circuit boards requires operatorswith specialized training and skill to handle, terminate, dress, andrestrain the optical fibers so that they survive the rigors of theaerospace environment, assembly costs for avionics manufacturers aredriven upward and the number of available contract manufacturers islimited to those with fiber-optics manufacturing expertise. While theexample of “avionics modules” is used here as a primary example, it isnoted that the problems described herein with realizing fiber-opticinterfaces in electronics modules pertain to application in many otherfields, and the usefulness of the invention described herein istherefore not limited to the avionics industry.

Another prior art approach attempts to provide for the use of opticalfiber, for example, in an overall avionics environment external tomodules while eliminating the need to route optical fiber within theavionics module itself. Generally, this approach moves the opticalconverter into the module interface. One example of a prior art attemptthat adopts this approach is seen in U.S. Pat. No. 7,690,849(hereinafter, the '849 Patent). The patent teaches an “active opticalcontact” for use in size-8 cavities in ARINC connectors and incorporatesits conversion hardware entirely into the size-8 contact body.

In the '849 Patent, the optical converter is soldered to alongitudinally-mounted printed circuit board (PCB). The same PCBsupports electrical interface pins on an opposing end thereof havinginternal ends which are also soldered to the PCB. The entire PCB is thensealed into a contact body using an epoxy potting material such thatprojecting or external ends of the interface pins project outwardly forpurposes of externally electrically interfacing the contact. Applicantsrecognize that this design is problematic for a number of reasons. Forexample, the optical connection of the optical converter is positionallyfixed and cannot float or move with resilient axial biasing toeffectively accommodate blind-mating, for example, in accordance withARINC requirements that are set forth for passive fiber-opticconnectors. At the same time, the configuration of the electricalinterface pins, for external electrical connection, is constrained basedon connecting to one or both surfaces of the PCB. The limitations on pinlocation can become serious when it is remembered that the diameter ofthe contact body can be very small in the first instance. Anotherconcern arises, based on this design, when it is desired to form solderconnections to the projecting ends of the electrical interface endssince the soldering process used to attach the unit to an external PCBis constrained to the use a solder having a significantly lower meltingtemperature than the solder used to attach the internal ends of the pinsto the PCB. This is especially problematic when non-leaded solders aremandated to satisfy the requirements of RoHS (Reduction of HazardousSubstances) act of the European Union. These concerns as well as relatedconcerns may be addressed at one or more appropriate points hereinafter.

The foregoing examples of the related art and limitations relatedtherewith are intended to be illustrative and not exclusive. Otherlimitations of the related art will become apparent to those of skill inthe art upon a reading of the specification and a study of the drawings.

SUMMARY

The following embodiments and aspects thereof are described andillustrated in conjunction with systems, tools and methods which aremeant to be exemplary and illustrative, not limiting in scope. Invarious embodiments, one or more of the above-described problems havebeen reduced or eliminated, while other embodiments are directed toother improvements.

In general, embodiments, systems and methods are described in relationto an opto-electronic contact. In one aspect of the present disclosure,the contact includes an opto-electronic converter including a converterlength extending between opposing first and second ends. The first endbeing configured for removable optical engagement with a fiber opticconnector, or other suitable component, and the second end including aconverter electrical connection arrangement. A barrel housing defines aninterior cavity characterized by an elongated length defining anelongation axis extending between opposing first and second barrelopenings for receiving the opto-electronic converter in the interiorcavity to provide for limited relative movement between the barrelhousing and the opto-electronic converter with the first end of theopto-electronic converter supported in the interior cavity proximate tothe first barrel opening for external optical engagement to the opposingfiber optic connector via the first barrel opening. A flexible circuitboard assembly includes an internal electrical connection end, anexternal electrical connection end and an elongated length extendingtherebetween. The internal connection end electrically engages theconverter electrical connection arrangement of the opto-electronicconnector and the external connection end is fixedly positionedproximate to the second barrel opening for external electricalconnection to the contact such that the external connection end ispositioned on the elongation axis at a distance from the second end ofthe opto-electronic connector that is less than the elongated length ofthe flexible circuit board and the elongated length is captured withinthe interior cavity of the barrel housing.

In another aspect of the present disclosure, an opto-electronic contactincludes an active opto-electronic converter including a converterlength extending between opposing first and second ends to define aconverter axis with the first end being configured for removable opticalengagement with a fiber optic connector. A barrel housing defines aninterior cavity having an elongated length extending between opposingfirst and second barrel openings to define an elongation axis and havingthe opto-electronic converter captured in the interior cavity forexternal optical engagement to the fiber optic connector via the firstbarrel opening for relative movement of the converter axis along theelongation axis, transverse thereto, and oblique thereto to accommodatemating tolerances responsive to engaging the fiber optic connector.

In still another aspect of the present disclosure, a method is disclosedto compensate for mating tolerances when mating an opto-electroniccontact to an opposing fiber optic connector. The method includesconfiguring a barrel housing defining an interior cavity having anelongated length extending between opposing first and second barrelopenings to define an elongation axis. An opto-electronic converter issupported in the interior cavity in a way that isolates the converterfrom mating misalignment responsive at least to engaging the opposingfiber optic connector by capturing the converter in the interior cavityfor external optical engagement to the fiber optic connector via thefirst barrel opening for relative movement of the converter axis alongthe elongation axis, transverse thereto, and oblique thereto toaccommodate mating tolerances responsive to engaging the opposing fiberoptic connector.

BRIEF DESCRIPTIONS OF THE DRAWINGS

Exemplary embodiments are illustrated in referenced figures of thedrawings. It is intended that the embodiments and figures disclosedherein are to be illustrative rather than limiting.

FIG. 1 is a diagrammatic view, in perspective of an embodiment of anopto-electronic contact that is produced according to the presentdisclosure.

FIG. 2 is a diagrammatic, partially cutaway view, in elevation, of anembodiment of a standard connector system supporting the opto-electroniccontact of FIG. 1 for blind mating with an opposing connector.

FIG. 3 is a diagrammatic exploded view, in perspective, of an embodimentof contact 10 of FIG. 1.

FIG. 4 is a further enlarged diagrammatic cutaway view, in perspective,of an embodiment of a barrel housing that can form part of the contactof FIGS. 1-3.

FIG. 5 is a diagrammatic view, in perspective, of an assembly includingan opto-electronic converter and flexible circuit board assembly thatcan be used in embodiments of the contact of the present disclosure suchas, for example, those of FIGS. 1-3.

FIG. 6 is another diagrammatic view, in perspective, of the assembly ofFIG. 5 shown as partially cutaway to reveal details of its internalstructure.

FIGS. 7 and 8 are diagrammatic views, in perspective, showing details ofa flexible circuit board assembly that can be used in embodiments of thecontact of the present disclosure.

FIG. 9 is a diagrammatic exploded view, in perspective, of an embodimentof the flexible circuit board assembly of the present disclosure, shownhere to illustrate details with respect to the use of a flexible circuitboard substrate in a sandwiched/layered overall structure.

FIG. 10 is a diagrammatic view, in perspective, of another embodiment ofan opto-electronic converter according to the present disclosure.

FIG. 11 is another diagrammatic view, in perspective, of still anotherembodiment of an opto-electronic converter according to the presentdisclosure.

FIG. 12 is a diagrammatic partially cutaway view, in perspective,showing the internal structure of the opto-electronic converter of FIG.11 in relation to selected external optical elements.

FIG. 13 is a diagrammatic partially cutaway view, in perspective,illustrating an assembled embodiment of an opto-electronic contactaccording to the present disclosure using, by way of non-limitingexample, the opto-electronic converter of FIGS. 11 and 12.

FIG. 14 is a diagrammatic view, in perspective, illustrating anassembled embodiment of an opto-electronic contact according to thepresent disclosure including a flexible circuit board extension whichextends outside of a barrel housing of the contact for externalelectrical connection purposes.

DETAILED DESCRIPTION

The following description is presented to enable one of ordinary skillin the art to make and use the invention and is provided in the contextof a patent application and its requirements. Various modifications tothe described embodiments will be readily apparent to those skilled inthe art and the generic principles taught herein may be applied to otherembodiments. Thus, the present invention is not intended to be limitedto the embodiment shown, but is to be accorded the widest scopeconsistent with the principles and features described herein includingmodifications and equivalents, as defined within the scope of theappended claims. It is noted that the drawings are not to scale and arediagrammatic in nature in a way that is thought to best illustratefeatures of interest. Descriptive terminology may be used with respectto these descriptions, however, this terminology has been adopted withthe intent of facilitating the reader's understanding and is notintended as being limiting. Further, the figures are not to scale forpurposes of illustrative clarity.

Turning now to the figures wherein like components may be designated bylike reference numbers throughout the various figures, attention isimmediately directed to FIG. 1 which is a diagrammatic view, inperspective, illustrating an embodiment of an opto-electronic contactthat is produced in accordance with the present disclosure and generallyindicated by the reference number 10. Contact 10 can be either atransmitter optical subassembly (TOSA) or a receiver optical subassembly(ROSA). In the instance of the former, the contact can include, forexample, a laser diode and associated drive electronics while, in theinstance of the latter, the contact can include, for example, aphotodiode and associated electronics. Generally, contact 10 can includea barrel housing 20 having an elongated length that can define anelongation axis 22 that is illustrated by a dashed line. The housing canbe formed having indexing features such as, for example, one or moreflats 24 for use in embodiments that benefit from indexing of therotational orientation, as will be further discussed. While the housingand overall contact 10 may be described below in terms of satisfying thestandards to meet a particular type of specification, it should beunderstood that the assembly can be configured to satisfy any suitableconnector specification, either currently in existence or yet to bedeveloped. Housing 20 can be configured to receive an alignment sleeveretainer cap 26, for example, using threaded engagement and having anO-ring groove that receives an O-ring 28. An opposing end of housing 20can support an external electrical connection interface 30 which, in thepresent example, includes an arrangement of electrically conductive pins32. As will be seen, pins 32 can be arranged in any suitable geometricpattern. In other embodiments, electrical interfacing can beaccomplished using suitable expedients other than electricallyconductive pins. In the embodiment of FIG. 1, straight electrical pinsare shown for clarity, but it is noted that some or all of the pins maybe replaced with other high-speed electrical interconnection means, suchas coax, twinax, or quadrax interconnections, or a flexible circuitboard, as appropriate for the signal type being transmitted. The barrelhousing and alignment sleeve retainer cap can be formed from suitablematerials including, but not limited to stainless steel or aluminum.

Referring to FIG. 2, in conjunction with FIG. 1, the former is adiagrammatic, partially cutaway view that illustrates a standardconnector system, generally indicated by the reference number 60, whichis suitable, by way of non-limiting example, for use in the avionics andaerospace industries. In particular, system 60 can conform to thewell-known ARINC 600 standard and includes a receptacle connector 64that defines three bays (not shown) for purposes of receiving insertsthat can support electrical and/or optical interconnections, even thoughthe original intent of the standard was to support electricalinterconnections. According to the standard, a plug connector 66 can bereceived in each bay of receptacle connector 64, by way of blind mating,having the receptacle connector mounted on a module and plug connector66 mounted in a bay of a rack assembly. In the present example,receptacle connector 64 can support a plurality of opto-electroniccontacts 10, only one of which is shown. In an embodiment, one insert inthe receptacle connector can support eleven instances of opto-electroniccontact 10. Electrical connection interface 30 of each contact can beelectrically connected, for example, to a printed circuit board 70 thatcan be located in a module such as an avionics module. Contact 10 isreceived in a cavity 74 which can be referred to, in the presentexample, as a size-8 cavity that can comply with the ARINC 801 standard.As noted above, this standard pertains to passive optical connectors forblind-mate interfaces having a diameter of approximately 8 mm.Opto-electronic contact 10 includes an annular shoulder 80 that isseatable against an annular floor within the receptacle cavity. Thecontact can be inserted from a front or exterior side 82 of receptacleconnector 64 (i.e., “front-release” type) such that an annular retentionclip 86 removably snaps into position over shoulder 80 to retain thecontact within the receptacle cavity. Other connector types can alsomake use of this type of contact, in either front-release orrear-release configurations.

Referring to FIG. 2, plug connector 66 defines a cavity that canreceive, by way of non-limiting example, an opposing contact 90. Theopposing contact can be optical or opto-electronic. An opposing opticalcontact can be “passive”, as in an optical fiber ferrule. An opposingopto-electronic contact can be “active”, incorporating electronicsand/or opto-electronic devices, for example, as taught herein. In thepresent example, the opposing contact supports a fiber optic cable 92that is terminated by a ferrule 94 to support an optical fiber such thatthe ferrule tip can be directly biased in physical contact against anopposing ferrule tip to provide for optical communication between twooptical fibers as detailed, for example, in ARINC 801. It should beappreciated that, while contact 90 can be characterized as a fiber opticcontact, a wide variety of physical outlines and/or standards can beemployed for contact 90 while remaining within the scope of the presentdisclosure so long as the contact is configured for optical engagement.In some embodiments, contact 90 can be an active contact which can evenbe produced according to the teachings that have been brought to lighthereinafter. In the present example, contact 90 is configured to engagean opposing ferrule in receptacle connector 64 that is identified by thereference number 100 and is provided as part of contact 10, as will befurther described. For the moment, it is sufficient to note that ARINC801 sets forth details relating to the positional relationship betweenthe opposing ferrules as the opposing contacts are partially engaged andthen reach full engagement. Other specifications, such as MIL-T-29504,MIL-C-28876 and others also describe similar detailed relationshipsbetween the opposing ferrules in optical contacts. In the presentexample, ferrule 100 does not form part of a passive fiber opticconnection but rather forms part of opto-electronic contact 10, as willbe further described, with respect to subsequent figures.

Attention is now directed to FIG. 3 which is a diagrammatic explodedview, in perspective, of an embodiment of contact 10 that is providedfor purposes of illustrating the various components that make up itsoverall structure. An opto-electronic converter 200 is appropriatelyconfigured to generate light in the instance of a TOSA embodiment or toreceive light in the instance of a ROSA embodiment, as described above.The converter, by way of example, can include electrical interface pins202 for external electrical connection. The converter also includesferrule 100 supported for optical communication with an internallysupported component which is shown in a subsequent figure. Ferrule 100can be formed, for example, as a molded ceramic from any suitablematerial. A precision alignment sleeve 204 can be provided in a splitconfiguration to be slidingly received on ferrule 100, interposedbetween alignment sleeve retainer cap 26 and the ferrule itself. Thealignment sleeve can have a length along elongation axis 22 (FIG. 1)that is longer than the protruding length of ferrule 100 such that thetip of the ferrule is housed and supported within sleeve 204. In thisregard, an outward end of the precision alignment sleeve is identifiedby the reference number 210 in FIG. 2. Thus, opposing ferrule 94 extendsinto alignment sleeve 204 when contact 90 is mated with contact 10 withthe intent of physically contacting ferrule 100, and thus enablingoptical communication between the tips of the respective ferrules. FIG.4 is a further enlarged and partially cut-away view of barrel housing 20shown here to illustrate further details of its structure. Inparticular, the barrel housing defines an annular groove 214 that isconfigured for supporting opto-electronic converter 200 in a manner thatis yet to be described.

Referring now to FIG. 5, attention is now directed to further detailswith respect to opto-electronic converter 200 and a flexible circuitboard assembly 300 that is used to interface the opto-electronicconverter to the outside world via external electrical connectioninterface 30 which, in an embodiment, supports an arrangement ofelectrically conductive pins 32. In this regard, a particular pin 32′can include an enlarged diameter or other suitable feature for indexingpurposes. The flexible circuit board assembly includes an internalelectrical connection end 304 for connection to electrical interfacepins 202 of the converter and an external electrical connection end 310for connection to electrically conductive pins 32. A middle section 314can be supported transversely or orthogonally to an elongation axis 316,shown as a dashed line, of the converter using the flexible circuitboard assembly. Generally, elongation axis 316 of the converter cancoincide with elongation axis 22 of the barrel housing when theconverter is installed in the barrel housing, although this is not arequirement. As will be further described, however, mating contact 10with opposing contact 90 typically produces misalignment between thesetwo axes since both the contact and the opposing contact are configuredto float in a way that provides for relative movement or float thataccommodates this misalignment to avoid damaging components of thecontact and/or components of the opposing contact. In the presentembodiment, the flexible circuit board assembly includes a first flexextension 320, extending from internal electrical connection end 304 tomiddle section 314, and a second flex extension 322 extending fromexternal electrical connection end 310 to middle section 314. First flexextension 320, in the present embodiment, includes two 180° bends suchthat the extension passes transversely through the elongation axis ofthe overall assembly whereas second flex extension 322 defines one 180°bend such that a total of 540° of bending is defined. In this regard,however, it should be appreciated that the flex extensions can beconfigured in any suitable manner and the configuration is not limitedto the described embodiment. As seen in FIG. 1, the opto-electronicconverter and flexible circuit board assembly are configured to bereceived in the interior cavity of barrel housing 20 such that pins 32extend outward from the barrel housing for purposes of forming anexternal electrical connection, although in other embodiments such anexternal electrical connection can be formed in different ways, as willbe further described. When installed, the flexible circuit boardassembly is fixedly attached at internal connection end 304 and externalconnection end 310 such that converter 200 can move relative to barrelhousing 20. In this regard, external connection end 310 can be fixedlysupported at the electrical connection end of the barrel housing in asuitable manner such as, for example, using an adhesive material orpotting compound which can also form an environmental seal between thebarrel housing and the external electrical connection end. Suitableadhesives and/or potting compounds include, but are not limited toepoxy, and RTV sealant as well as suitable combinations thereof. At thesame time, and as will be further described, flex extensions 320 and322, and middle section 314, depending on the extents of any pottingcompound that is used, can move relative to the barrel housingresponsive to relative movement of converter 200. It should beappreciated that flex extension 320 can be configured, in an embodiment,to provide for more than adequate relative movement even when middlesection 314 and an initial portion of flex extension 320 proximate tothe middle section are encased in potting compound wherein pottingcompound 323 is indicated by a dashed line in FIG. 5.

Referring collectively to FIGS. 3-5, relative movement between barrelhousing 20 and converter 200, in addition to the use of flexible circuitboard assembly 300, is facilitated by the manner in which the barrelhousing supports the converter. In the present embodiment, a retentionclip 400 includes an annular configuration that is receivable around acollar 402 (best seen in FIG. 3) that is defined between a main body 408of the converter and a flange 410 which terminates the collar. Anindexing feature 412, indicated by dashed lines, can be formed, forexample, as part of a peripheral outline of the converter body tocooperate with a complementary feature that can be defined on theinterior of the barrel housing. Examples of suitable indexing featuresinclude but are limited to one or more slots or projections arrangedaround the periphery of the converter body. Such indexing is useful, forexample, when an angle polished ferrule (APC) is used as ferrule 100 forpurposes of establishing the rotational orientation of the converter,and thereby the ferrule, to within some tolerance of a known position.Indexing feature(s) 412 can cooperate with flats 24 (see FIGS. 1, 3 and4) to ensure that the opto-electronic contact is placed into a knownrotational orientation in confronting opposing contact 90, as seen inFIG. 2. The retention clip can be formed, for example, from a suitablyresilient material such as, for example, spring steel, orberyllium-copper in a “C” configuration such that the retention clip canbe installed on the collar by spreading the opening in the C shape. Theretention clip is shown as installed in FIG. 5 and is slidingly receivedon collar 402. The inside diameter of the retention clip can be sized toprovide a suitable amount of clearance relative to the collar such thatthe plane of the retention clip can twist and form an angle relative toelongation axis 316 of the converter for reasons which will be madeevident. In the present embodiment, a coil spring 414 is also installedon collar 402 such that the coil spring is captured between collar 402and retention clip 400. Converter 200 can be received in the cavity ofbarrel housing 20 with retention clip 400 biased against a shoulder 416(FIG. 4) of the barrel housing. In this way, movement of ferrule 100responsive to engagement/disengagement with an opposing contact allowsthe converter to move relative to the barrel housing in any manner thatis needed to accommodate proper optical engagement with an opposingferrule. For example, the converter can move axially along elongationaxis 22 of the barrel housing such that the tip of ferrule 100 isresiliently biased against the tip of an opposing ferrule. Such axialmovement can cause dynamic compression and/or expansion of spring 414.The converter can also move in any direction radially transverse to axis22 of the barrel housing. Further, as shown in FIG. 5, ferrule 100 cantwist or rotate to form an angle α that is defined between elongationaxis 316 of the converter and elongation axis 22 of the barrel housing.This angle can be up to 10 degrees. With regard to this feature,Applicants note that nonzero values of angle α are typically observedwhen opposing contacts are properly mated. Furthermore, the angle αshould be able to dynamically self-adjust in response to the opposingaction of the two optical ferrules 94 and 100 through the split-sleeve204 during engagement, until full contact-to-contact optical mating isachieved. Thus, the converter is supported effectively only by retentionclip 400 and centered, at least within some tolerance, within the cavitythat is defined by the barrel housing. It is noted that the converterand clip along with any associated spring are installed from theenlarged diameter end of barrel housing 20. It is further noted that incertain embodiments, spring 414 is not used, in which case the converterhas minimal axial float along elongation axis 316, but still may move inany direction radially transverse to axis 22, or can form angle αbetween elongation axis 316 of the converter and elongation axis 22 ofthe barrel housing. This type of embodiment can be acceptable insituations where the opposing contact incorporates adequate springtravel and force to cause effective physical contact of the opposingoptical ferrules in the fully-mated condition, under all conditions,including mechanical tolerances, thermal expansion, vibration, shock,and the like.

FIG. 6 is another diagrammatic view, in perspective, of the embodimentsof opto-electronic converter 200 and flexible circuit board assembly 300shown in FIG. 5. In this instance, however, converter 200 is shown aspartially cut-away to reveal details of its internal structure. Inparticular, converter 200 includes an optical converter element 460 suchas, for example, a laser diode or solid state detector that is supportedin an internal housing 464 and suitably electrically interfaced tointerface pins 202 of the converter. Housing 464, in an embodiment, canbe in the form of a well-known Transistor Outline (TO) package such as aTO-46 package that supports a lens 470. While any suitable lens can beused, the present embodiment illustrates the use of a ball lens with raytraces 474 included to illustrate optical coupling and focusing betweenoptical converter element 460 and a confronting end of an optical fiber480 that is supported by ferrule 100. In the present embodiment, thedistal/exterior end of fiber 480 and ferrule 100 are flat polished whilethe interior end can be angle-polished, for example, at a suitable anglesuch as at least approximately 8 degrees to direct reflections outsideof the overall optical path that is defined by the assembly.

Attention is now directed to FIGS. 7 and 8 which are diagrammatic views,in perspective, of flexible circuit board assembly 300 showing each ofthe opposing major surfaces of the assembly in a planar form forpurposes of illustrating details of its structure. In this regard, itshould be appreciated that first flex extension 320 between internalelectrical connection end 304 and middle section 314 is significantlylonger than second flex extension 322 between external electricalconnection end 310 and middle section 314 to support bending as shown inFIGS. 3, 5 and 6, although other bending arrangements may be found to besuitable. Middle circuit section 314 can support an amplifier 500, asseen in FIG. 7. In the case of opto-electronic converter 200 including alight emitting element such as a laser diode, amplifier 500 can be adriver amplifier. On the other hand, in the case of opto-electronicconverter 200 including a light detector or receiver element such as aphotodiode, amplifier 500 can be a limiting amplifier. The middlesection on the side opposite of amplifier 500, as seen in FIG. 8, cansupport any suitable arrangement of electrical components 504 such as,for example, passive components such as, for example, passive electricalcomponents for purposes which include but are not limited to decouplingor impedance-matching of data transmission lines, biasing of theopto-electronic device, and electrical tuning or filtering. In theinstance of a driver amplifier, the electrical connection to externalconnection end 310 can be by way of differential drive such that atleast some of passive components 504 can be used to terminate thedifferential drive arrangement in its characteristic impedance. For alaser diode that is intended to operate over a wide temperature range,at least some of components 504 can be passive components that aredirected to providing temperature compensation. External electricalconnection end 310 supports electrically conductive pins 32 which can belaid out in any suitable manner, as will be further discussed. In anembodiment, pin 32′ can serve as a ground pin and be of an enlargeddiameter or any other suitable shape/configuration relative to the otherpins to serve an indexing function. As seen in FIG. 8, the externalelectrical connection end can support electrical components 510 such as,for example, passive electrical components for purposes which caninclude, but are not limited to de-coupling, tuning and/orimpedance-matching of the electrical data transmission lines, andfiltering of electrical input power lines. Internal electricalconnection end 304 is configured to engage the electrical interfacearrangement of opto-electronic converter 200 such as, for example,interface pins 202 (FIG. 3) using a pattern of through holes 512 each ofwhich can be surrounded by an electrically conductive trace. In anembodiment, pins 202 can be soldered to internal electrical interfacearrangement 304. In some embodiments, the internal electrical interfacearrangement can support electrical components 514 (FIG. 7) such as, forexample, passive electrical components for purposes which include butare not limited to decoupling or impedance-matching of data transmissionlines, biasing of the opto-electronic device, and electrical tuning orfiltering.

Attention is now directed to FIG. 9, which is a diagrammatic explodedview, in perspective, of an embodiment of flexible circuit boardassembly 300, shown here to illustrate still further details of itsstructure. In particular, a flexible circuit substrate 520 includes anelongated length 522 that can extend along the full end-to-end length ofthe assembly. Flexible substrate 520 can be formed from any suitablematerial such as, for example, polyimide or “Kapton”, and can supportelectrically conductive traces 524 (diagrammatically shown) that arelaid out in a desired pattern for purposes of forming electricalconnections. In the present embodiment, a sandwich construction isapplied for purposes of forming internal electrical connection end 304,external connection end 310, and middle section 314. Internal connectionend 304 can include first and second circuit boards 530 a and 530 barranged on opposing sides of flexible substrate 520. Boards 530 a and530 b can be formed from any suitable material such as, for example, FR4and patterned with electrically conductive traces for electricalcommunication with cooperative electrically conductive traces defined onflexible substrate 520. Through holes 534, with surrounding electricallyconductive traces, can be arranged to align with through holes 512 ofthe flexible substrate to receive electrically conductive pins 202 ofthe opto-electronic converter. Boards 530 a and 530 b can be fixedlyattached to the flexible substrate, for example, by solder and/orsuitable adhesives. In another embodiment, the internal electricalconnection end of the flexible substrate can be attached to pins 202without using rigid circuit boards or using only one of the rigidcircuit boards. In this regard, flexible substrate 520 can directlysupport electrical components 514. Moreover, in another embodiment, theentire circuit board may be comprised of a flexible substrate only, withno rigid sections, onto which electrical amplifier 500 and otherelectrical components 514 may be directly affixed by solder and/orsuitable adhesives.

Still referring to FIG. 9, external connection end 310 can be configuredincluding opposing rigid circuit boards 550 a and 550 b in the mannerdescribed above for the internal connection end. Openings 554 defined inthe external connection end of the flexible substrate align withopenings 556 of boards 550 a and 550 b to receive pins 32 and 32′subsequent to attachment of boards 550 a and 550 b to the flexiblesubstrate. In an embodiment, pins 32 and 32′ can be installed in theexternal connection end using a pressed-fit. In such an embodiment, thepins can include an annular shoulder 558 and a patterned region 560 suchas, for example, a splined configuration which accommodates the pressedfit, or a “swage” type of construction. After the pins are pressed intothe external connection end, solder can be applied to electricallyconnect the pins to electrically conductive patterns on each of boards550 a and 550 b as well as to the pattern on flexible substrate 520. Itshould be appreciated that the use of a pressed-fit, in the presentembodiment, establishes the pin positions in a way that is resistant toshifting of the pins during soldering. In this regard, maintaining thepins in predetermined positions or at least within some desiredtolerance from such predetermined positions can ensure ease ofinstallation of the pins of interface 30 into circuit board 70 of FIG. 2while avoiding damage to the pins and/or circuit board 70. Anotherbenefit is provided with respect to flexibility in the installationpattern of the pins of interface 30. Since the pins are installedthrough the major surfaces of boards 550 a and 550 b, there are fewconstraints on the pin locations. In contrast, the '849 patent attachespins to circuit board edges in a highly constrained way which limits thearrangement of the pins to one row or two narrowly spaced apart rowsthat are spaced apart by only the thickness of the printed circuitboard. In this regard, the reader is reminded that the diameter ofbarrel housing 20, in the instance of ARINC 801, can be very small atapproximately only approximately 0.275 inch or 6.97 mm which serves tofurther increase concerns that arise through limitations imposed on pinlocations. Also, as described in the '849 patent, the attachment of thepins to the edges of the internal circuit board using solder is muchmore susceptible to damage by excessive heating of the pins duringsoldering to external circuit board 70, with permanent damage to thecontact in the form of electrical open circuits or short circuitspossible due to reflowing of the solder internal to the contact. Thispossibility is mitigated by the press-fit or swage construction broughtto light by the Applicants.

Middle section 314 can be configured including opposing rigid circuitboards 580 a and 580 b in the manner described above for the internaland external connection ends. Printed circuit board 580 a can bepatterned based on the requirements of amplifier 500 whereas printedcircuit board 580 b can be patterned to support any additionalelectrical components that are needed such as, for example, passivecomponents including any suitable arrangement or combination ofresistors, capacitors and/or inductors 504 (see FIG. 8).

With continuing reference to FIG. 9, in other embodiments, one or bothof first flex extension 320 and second flexible extension 322 can beindividually formed and electrically connected, for example, bysoldering, to a rigid printed circuit board that serves as any one ofthe internal connection end, the external connection end and/or themiddle section.

Attention is now directed to FIG. 10 which illustrates anotherembodiment of an opto-electronic converter, indicated by the referencenumber 200′ which can be used in contact 10 of FIGS. 1-3. Converter 200′is shown in a diagrammatic, perspective view. The present discussion islimited to those features which differentiate converter 200′ frompreviously described converter 200 for purposes of brevity. The readeris directed to the discussion of converter 200, which appears above, fordetails with respect to components and features that are shared by thetwo embodiments under immediate consideration. Converter 200′ includes aretention clip 400′ installed on collar 402 without the use of aresilient biasing element such as previously described coil spring 414.Clip 400′ can include an annular rim 600 that is configured to bereceived in annular groove 214 (FIG. 4) of barrel housing 20, forexample, by receiving clip 400′ into groove 214. Clip 400′ can include askirt 602, extending from annular rim 600 and having a length along theaxis of the converter that is based on the axial length of collar 402such that predetermined tolerances are established between clip 400′,collar 402 and flange 410. These tolerances provide for movement ofconverter 200′ relative to barrel housing 20 such that the converter canfloat relative to the barrel housing when another contact such as, forexample, opposing contact 90 of FIG. 2 is engaged. It is noted that theopposing/confronting ends of clip 400′, which define a gap therebetweenfor purposes of installing the clip onto collar 402, can be spaced apartby any suitable angular offset. Clip 400′ can be formed from anysuitable material such as, for example, tempered spring steel orberyllium-copper.

Turning to FIG. 11, another embodiment of an opto-electronic converter,generally indicated by the reference number 200″ is shown in adiagrammatic, perspective view. Like converter 200′, converter 200″ canbe used in contact 10 of FIGS. 1-3. Accordingly, the present discussionis limited to those features which differentiate converter 200″ frompreviously described converters 200 and 200′ for purposes of brevity.The reader is directed to the discussion of converters 200 and 200′,which appear above, for details with respect to shared components andfeatures that are illustrated. Converter 200″ can include previouslydescribed retention clip 400 installed on collar 402. In the presentembodiment, however, a wave spring 660 is received on collar 402 suchthat the wave spring is captured between retention clip 400 and flange410. Wave spring 660 can be installed on collar 402 in the mannerdescribed above with regard to helical coil spring 414 by spreading theopposing ends of the wave spring apart to a degree that allowsinstallation on the collar. As described above, retention clip 400 isresiliently receivable in groove 214 (FIG. 4) such that axial movementof converter 200″ can occur relative to barrel housing 20 much in thesame manner as is provided by previously described coil spring 414.Responsive to compression that displaces converter 200″ further into thebarrel housing, the opposing ends of the wave spring can move toward oneanother and/or overlap. In the present embodiment, a gap 664 between theopposing ends of the wave spring can be aligned with a gap 668 betweenthe opposing ends of clip 400, although this is not a requirement. Thewave spring, for a given axial length of collar 402 can provide for arelative increase in the amount of axial movement that is available forthe converter relative to the housing since the wave spring can becompressed to essentially the thickness of the material from which it isformed, whereas a coil spring can compress only to the point thatadjacent coils of the spring are in physical contact. In this regard, itshould also be noted that the axial length of collar 402 can becustomized based on the use of a given type of spring and the amount ofaxial movement that is to be provided. Wave spring 660 can be formedfrom any suitable material including, but not limited to tempered springsteel or beryllium-copper. The use of the wave spring provides for thesame relative movement of the converter relative to the barrel housingin addition to resiliently biased axial movement. For example, theconverter can also move in any direction radially transverse to axis 22(FIG. 1) of the barrel housing. Further, as shown in FIG. 5, likeferrule 100, an optical communication end 670 can twist or rotate toform aforedescribed angle α (FIG. 5) that is defined between elongationaxis 316 of the converter and elongation axis 22 of the barrel housing.It should be apparent through a comparison of FIGS. 10 and 11, thatanother difference with respect to converter 200″ resides in theconfiguration of optical communication end 670 which internally supportsferrule 100 (FIGS. 2, 3, 5, 6 and 10), as will be described in furtherdetail immediately hereinafter.

FIG. 12 is a diagrammatic cutaway view, in perspective, whichillustrates further details of converter 200″ of FIG. 11. Initially, itis noted that converter 200 of FIG. 3 is supported such that the endface or tip of ferrule 100 can physically contact the tip of an opposingferrule to provide for optical communication therebetween. Converter200″, however, is configured for use in a free space collimatedconfiguration having a collimating lens 700 in contact, or near contact,with the tip of ferrule 100 such that light 702, which can be collimatedto a degree that is sufficient for optical coupling purposes, can travelthrough an empty cavity between collimating lens 700 and an opposingcollimating lens 704, shown in phantom using dashed lines, that isitself in optical communication with an opposing ferrule 706, with thelatter only partially shown and illustrated in phantom using dashedlines. It should be appreciated that light 702 can be traveling ineither direction and that collimating lens 704 and opposing collimatinglens 700, in general, are selected to couple to and from the collimatedlight beam 702 of predetermined characteristics. Therefore, they may beidentically constructed lenses, or different, depending on the type offiber being used on each side of light beam 702, or other designconstraints. In an embodiment, these lenses can be ball lenses. Inanother embodiment, these lenses can be graded-index (GRIN) lenses orany suitable type of lens.

Referring to FIG. 13 in conjunction with FIGS. 11 and 12, the former isa diagrammatic cutaway view in elevation of contact 10 supportingopto-electronic converter 200″ of FIG. 12. It should be appreciated thatthe contact varies little in appearance when either converter 200 orconverter 200′ are installed, hence these additional views have not beenprovided for purposes of brevity. Exceptions in the appearance of thesefigures would entail deleting collimating lens 700 and modifying theappearance of precision alignment sleeve 204, as well as changing theappearance of the retention clip and associated spring that are used,depending on the particular embodiment. It is noted that the assembly isshown in an unmated state such that retention clip 400 is resilientlybiased against shoulder 416 (see also FIG. 4) by wave spring 660. At thesame time, flange 410 is received against an inner surface 720 ofalignment sleeve retainer cap 26. Mating contact 10 with an opposingcontact generally causes some combination of axial movement in thedirection indicated by an arrow 704, lateral/radial movement orthogonalto the axial movement and angular twisting indicated by an arc 710. Thecombined movement provides for substantially reduced exposure of thecomponents of contact 10, as well as the opposing contact, to damage.Components that can be sensitive to damage include any precisionalignment sleeves that are in use. By damaging such components, theoptical coupling performance can be compromised, for example, byincreasing coupling losses. Accordingly, contact 10 provides a sweepingimprovement over prior art contacts such as are taught, for example, bythe '849 patent.

FIG. 14 illustrates an embodiment of contact 10 wherein interface 30 isaccomplished using another embodiment of the second flex extension whichis indicated by the reference number 322′. In particular, flex extension322′ includes a free end 800 that extends outside the end of the barrelhousing 20. Accordingly, a wide variety of electrical connection schemescan be employed in cooperation with flex extension 322′, For example,pins can be soldered to traces 804 to mate with an external connector.As another example, traces 800 can be soldered directly to anothercircuit board or the distal/free end of extension 322′ can be inserteddirectly into another connector or socket 810. If desired, traces 804can be terminated with electrical pads for soldering or other electricalconnection purposes. In an embodiment, connector 810 can be a zeroinsertion force (ZIF) connector. In still another embodiment, flexextension 322′ can itself support a connector that is external to barrelhousing 20.

Having described a number of embodiments above, it should be appreciatedthat a heretofore unseen opto-electronic contact, associated method andconnection system have been brought to light by the present disclosure.Such a contact can include an active opto-electronic converter includinga converter length extending between opposing first and second ends todefine a converter axis having the first end configured for removableoptical engagement with an opposing contact. A housing such as, forexample, a barrel housing can define an interior cavity having anelongated length extending between opposing first and second barrelopenings to define an elongation axis and having the opto-electronicconverter captured in the interior cavity for external opticalengagement to the opposing contact via the first barrel opening forrelative movement of the converter axis along the elongation axis,transverse thereto, and oblique thereto to accommodate mating tolerancesresponsive to engaging the opposing contact. In an embodiment, aflexible circuit board assembly includes an internal electricalconnection end, an external electrical connection end and an elongatedlength extending therebetween. The internal connection end electricallyengages the converter and the external connection end can be fixedlypositioned proximate to the second barrel opening for externalelectrical connection to the opto-electronic contact such that theexternal connection end is positioned on the elongation axis at adistance from the second end of the opto-electronic contact that is lessthan the elongated length of the flexible circuit board and theelongated length is captured within the interior cavity of the barrelhousing.

The foregoing description of the invention has been presented forpurposes of illustration and description. For example, in otherembodiments, the contact of the present disclosure can be configuredaccording to other connection system standards or specificationsincluding but not limited to an ELIO contact configuration, MILStandards 38999, 29504, 28776, 64266, and the like. Accordingly, thepresent application is not intended to be exhaustive or to limit theinvention to the precise form or forms disclosed, and other embodiments,modifications and variations may be possible in light of the aboveteachings wherein those of skill in the art will recognize certainmodifications, permutations, additions and sub-combinations thereof.

What is claimed is:
 1. An opto-electronic contact, comprising: an activeopto-electronic converter including a converter length extending betweenopposing first and second ends to define a converter axis and said firstend being configured for removable optical engagement with an opposingcontact; and a barrel housing defining an interior cavity having anelongated length extending between opposing first and second barrelopenings to define an elongation axis and having said opto-electronicconverter captured in the interior cavity for external opticalengagement to the opposing contact via the first barrel opening forrelative movement of the converter axis along said elongation axis,transverse thereto, and oblique thereto to accommodate mating tolerancesresponsive to engaging the opposing contact.
 2. The opto-electroniccontact of claim 1 wherein the opposing contact is one of an opposingopto-electronic contact and an opposing passive fiber optic contact. 3.The opto-electronic contact of claim 1 wherein the opto-electronicconverter is captured in the barrel housing such that theopto-electronic converter, when unmated to the opposing contact, is notresiliently biased against the barrel housing.
 4. The opto-electroniccontact of claim 1 including a support clip that engages an innerperipheral sidewall configuration of the barrel housing and an outerperipheral sidewall configuration of the opto-electronic converter tolimit movement of the opto-electronic converter in the barrel housing tosaid relative movement such that the opto-electronic converter isretained in the barrel housing.
 5. The opto-electronic contact of claim4 wherein the support clip is a C-shaped retaining ring.
 6. Theopto-electronic contact of claim 5 wherein said barrel housing defines abarrel housing groove in said inner peripheral sidewall and said outerperipheral sidewall configuration of the opto-electronic converterdefines a converter groove to cooperatively seat the C-clip.
 7. Theopto-electronic contact of claim 1 further comprising a support clipthat defines a support clip aperture and a support clip outer periphery,and an inner peripheral sidewall configuration of the barrel housing isconfigured to capture the support clip outer periphery having theopto-electronic converter slidingly received in the support clipaperture to provide said relative movement.
 8. The opto-electroniccontact of claim 7 wherein the opto-electronic converter defines a pairof confronting annular shoulders between which the support clip isslidingly received.
 9. The opto-electronic contact of claim 8 whereinsaid opto-electronic converter defines an at least generally cylindricalsurface that extends between said confronting annular shoulders andthrough said support clip aperture such that the support clip slidesalong said cylindrical surface.
 10. The opto-electronic contact of claim9 including a biasing spring having opposing spring ends and defining aspring aperture between the opposing spring ends through which the atleast generally cylindrical surface is received such that the opposingspring ends are resiliently captured between one of the annularshoulders and the support clip to at least provide for movement of theopto-electronic converter into the barrel housing along the elongationaxis by compressing the biasing spring responsive to engaging theopposing contact.
 11. The opto-electronic contact of claim 10 whereinthe support clip is resiliently seatable against the other one of theannular shoulders by the biasing spring when the contact is disengagedfrom the opposing contact.
 12. The opto-electronic contact of claim 10wherein the biasing spring is a coil spring.
 13. The opto-electroniccontact of claim 1 configured to cooperate with the opposing contact forfree space collimated coupling therewith.
 14. The opto-electroniccontact of claim 1 configured to engage the opposing contact in arotationally indexed orientation to provide a predetermined degree oftolerance in an engaged rotational orientation.
 15. The opto-electroniccontact of claim 14 including an angle polished configuration to engagea cooperating angle polished configuration on said opposing contact. 16.The opto-electronic contact of claim 14 wherein said opto-electroniccontact includes a peripheral outline having a keying arrangement toestablish the predetermined degree of tolerance.
 17. The opto-electroniccontact of claim 1, further comprising: a flexible circuit boardassembly having an internal electrical connection end, an externalelectrical connection end and an elongated length extendingtherebetween, said internal connection end electrically engaging theactive opto-electronic converter and said external connection endarranged proximate to the second barrel opening for external electricalconnection to the opto-electronic contact.
 18. The opto-electroniccontact of claim 17 wherein the external connection end is fixedlypositioned on the elongation axis at a distance from the second end ofthe opto-electronic converter that is less than an elongated length ofthe flexible circuit board and the elongated length is captured withinsaid interior cavity of the barrel housing.
 19. The opto-electroniccontact of claim 17 wherein an intermediate portion of the elongatedlength of the flexible circuit board assembly is fixedly captured at thesecond opening of the barrel housing such that the external electricalconnection end extends outward from the second opening of the barrelhousing as a free end for forming an external electrical interface.